This video presents an extended look at the MMDC ocean nursery for giant clams as it appeared in 1989. MMDC is the acronym for Micronesian Mariculture Demonstration Center in Koror, Palau. The facility is now (2010) called PMDC, the Palau Mariculture Demonstration Center.
By 1990 the MMDC ocean nursery contained over 10,000 mature, captive-bred broodstock of the threatened bivalve mollusc species Tridacna derasa, of ages 6-11 years post- fertilization. All of these T. derasa specimens were produced in the land-based tanks shown in the other videos on this YouTube channel. At the time this video was taken, this assemblage of mature clams constituted the world’s largest genetic repository, or gene bank, of captive-bred Tridacna derasa.
By the early 1990s the aggregate weight of the captive-bred clams in this nursery exceeded 100 tons.
With 10,000 mature broodstock clams, the adjacent MMDC hatchery had the capacity to conduct 250 spawning events per year (5 per week for 50 weeks per year), each with a “critical mass” of 40 specimens at a time, while still allowing a full one-year recovery period for each clam in the nursery before using it again for spawning.
Full reproductive independence from wild stocks of Tridacna derasa had thus been achieved. This represented an important milestone in the demonstration that tridacnid clams could be domesticated, with routine and reliable egg-to-egg control over their life cycle.
The sheer reproductive capacity of the MMDC ocean clam nursery and hatchery in 1990 had never been achieved elsewhere, and to our knowledge has not since been surpassed, for T. derasa or any other tridacnid clam species.
This facility remains in production today (September, 2010) as PMDC, the Palau Mariculture Demonstration Center.
Videography by Gerald Heslinga (NMFS/NOAA)
